How it works
First-month cash burn grows by a fixed percentage each subsequent month; spending is a geometric sum. This form solves for required starting cash (same currency); enter the known quantities in First-month cash burn (same currency), Monthly burn increase, Mathematical runway.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| First-month cash burn (same currency) | 10,000 | Formula symbol: burn. Enter a numeric value. Must be greater than zero. |
| Monthly burn increase | 10 % | Formula symbol: growth. Enter the percentage as a number: for 15%, enter 15. Use the monthly rate. Must be greater than zero. Allowed range: 0.001–100. |
| Mathematical runway | 5 mo | Formula symbol: months. Required unit: mo. Must be greater than zero. Allowed range: 0.001–1,000. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- First-month cash burn (same currency)
- 10,000
- Monthly burn increase
- 10 %
- Mathematical runway
- 5 mo
Complete example results
- Required starting cash (same currency)
- 61,051
Reading the result
The result solves for required starting cash (same currency) from the entered quantities. Check the result unit and the formula conditions before using it.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
When can I use the required starting cash (same currency) result?
Growth must be positive. The time solution is a continuous mathematical month equivalent; calendar payments need separate budgeting. New revenue or financing is excluded. All monetary inputs must use the same currency; currency conversion, tax and automatic fees are excluded. The source derives a finite geometric sum; here its first term is first-month burn and its common ratio is 1 plus monthly growth. A fractional month is the mathematical extension of that formula.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method sources: openstax.org